Abstract: Described herein is a process for the preparation of (1S,2R)-1,2-epoxy-1,2,3,4-tetrahydronaphthalene having the Formula (I): ##STR1## which comprises the steps of (a) hydrogenating the compound of Formula (II) to form cis-(1R, 2S)-1,2-dihydroxy-1,2,3,4-tetrahydronaphthalene having the Formula (V): ##STR2## (b) reacting the dihydroxy compound of Formula (V) with a sulphonyl halide of formula R.sup.1 SO.sub.2 Z wherein R.sup.1 is methyl, ethyl, trifluoromethyl, phenyl or p-tolyl, and Z is fluorine, chlorine, bromine or iodine to give a bis-sulphonyl ester of formula (X): ##STR3## and (c) treating the bis-sulphonyl ester (X) with an alkali metal carbonate or alkali metal hydroxide to give the compound of Formula (I).

Abstract: A process for the preparation of 1,1,1-trichlorotrifluoroethane in which 1-chloro-2,2,2-trifluoroethane is subjected to chlorination by bringing the 1-chloro-2,2,2-trifluoroethane into contact with chlorine within a reaction vessel characterized in that the process is conducted in the liquid phase in the presence of a chemical free radical initiator under a pressure of from 1 to 20 bar and at a temperature within the range 50.degree. to 120.degree. C., and the product is separated from the reaction mixture by fractional distillation.

Abstract: A process for preparing halogenated compounds of formula RCY(Z)CH.sub.2 CH(X)C(CH.sub.3)CH.sub.2 COR.sup.1 where X, Y and Z are halo, R is alkyl, halo, haloalkyl or aryl, and R.sup.1 is hydroxy, halo, alkoxy, alkyl or haloalkyl, or the residue of a pyrethroidal alcohol, in which a compound of formula CH.sub.2 =CHC(CH.sub.3).sub.2 COR.sup.1 is reacted with a sulphonyl halide of formula RCY(Z)SO.sub.2 X. The process avoids the use of volatile halocarbons in the production of valuable intermediates for insecticides.

Abstract: A process for the separation of a compound comprising a 1,2-dihydroxycyclohexa-3,5-diene ring from a medium containing it in which the compound reacts with a phenylboronate ion to form a phenylboronate ester which is insoluble in the medium. Novel phenylboronate esters formed during the separation process are also claimed.